Superconductivity is one of those bizarre phenomena that classical physics alone can't totally explain. Some materials, when cooled to temperatures near absolute zero, reach zero electrical resistance. Thus, an electric current can persist indefinitely.

Scientists use superconductive materials in particle colliders like the LHC, but you don't have to go all the way to Europe to do entertaining tricks with them. The persistent current in a superconductor can levitate materials, since the constant current repels the magnetic field of the levitating object, even a living one. Here, Dutch scientists levitate a frog in a 16-tesla magnetic field.